The Douglas-fir (scientific name: Pseudotsuga) is a genus of tree that includes ar least five species found in North America and Asia:
- Bigcone Douglas-fir (Pseudotsuga macrocarpa)
- Coast Douglas-fir (Pseudotsuga menziesii)
-- 'Pseudotsuga menziesii subsp. menziesii – regular Coast Douglas-fir
-- Pseudotsuga menziesii subsp. glauca – Rocky Mountain Douglas-fir
- Mexican Douglas-fir (Pseudotsuga lindleyana; included by some within Pseudotsuga menziesii subsp. glauca)
- Chinese Douglas-fir (Pseudotsuga sinensis)-- 'Pseudotsuga sinensis var. sinensis – regular Chinese Douglas-fir-- Pseudotsuga sinensis var. brevifolia – Short-leaf Chinese Douglas-fir (considered by some to be a separtae species)-- Pseudotsuga sinensis var. forrestii – Yunnan Douglas-fir (considered by some to be a separate species Pseudotsuga 'forrestii)-- Pseudotsuga sinensis var. gaussenii – Narrow-cone Chinese Douglas-fir-- Pseudotsuga sinensis var. wilsoniana – Taiwan Douglas-fir (considered by some to be a separate species Pseudotsuga 'wilsoniana)
- Japanese Douglas-fir (Pseudotsuga japonica)
The Douglas-fir is evergreen (has leaves in all seasons) and a conifer (a cone-bearing seed plant that includes such trees as pines, spruces, and firs) with needle-like leaves. The Douglas-fir is a gymnosperm, but is not classified as a true fir taxon, which appellation is reserved for genus Abies.
Possibly the tallest recorded land plant of any species might have been a specimen of P. mensziesii, claimed as 126.5 meters tall, in Lynn Valley at Vancouver, British Columbia, Canada, which tree is no longer living; another specimen of the same species, claimed as a height of 120.0 meters, was recorded in Mineral, Washington. However, neither claim is verified, and (like many old tree measurements) are unlikely to be accurate. The tallest currently known is 99 meters tall.
The conservation status of both Asian species is classified by the IUCN as Vulnerable, chiefly from overharvesting due to high population densities and demand for wood, especially in China. Not only are the North American species considered non-threatened species, but P. menziesii is considered an aggressive species in part of its range, especially in California, where aggressive fire suppression has placed this conifer in a niche that it can out-compete oak species, in locations which are historically oak-dominant woodlands.
The North American members of the genus are strongly associated with the celebration of Christmas, using the tree itself as a major decoration, as well as use of boughs for accent decoration and wreath-making.
The genus level characteristics of this [[plant] taxon] include the fact that young trees have conic crowns, with branches appearing branches manifested as whorled. Bark of young individuals is typically smooth with resin blisters, while mature bark exhibits a thick, deeply furrowed, dark brown appearance. Leaf scars are more or less smooth and round, slightly raised above the twig surface on persistent leaf bases. Buds are generally less than fifteen millimeters in length and are fusiform. Young trees often exhibit drooping limber branch architecture.
Leaves are needle-like and are typically persistent for less than eight years. These needles are generally 2.0 to 4.5 centimeters, tapered to a short petiole above a persistent base, generally spreading and flat, with two whitish bands on the lower leaf surface.
Seed cones are drooping, hanging, or suspended from a point of attachment above. These cones are typically pendant, four to twenty cm long, and maturing within the first season; these cones may be persistent or deciduous, and exhibit a stalk less than twocm. Bracts have a more or less exserted form, and are three-toothed or lobed at the tip, without scales. Seeds (including the wings) are normally less than 25 millimeters in size.
These trees typically grow to 25 meters tall and the trunk to 1.3 meters diameter at breast height (d.b.h).
The bark is reddish brown, aging dark blackish gray, scaly, and longitudinally fissured.
Branchlets are pendulous, reddish brown or pale brown, aging gray-brown, slender, flexible, and slightly pubescent.
Winter buds are reddish brown, ovoid-conical or fusiform-conical, and acute.
Leaves are 2.5-4 cm × ca. 2 mm, with two stomatal bands, abaxial, grayish white, base strongly twisted, apex acute.
Seed cones are greenish yellow when immature, ripening to dull brown, ovoid-cylindric, and 9-18 × 4-6 cm in size.
Seed scales at middle of cones are broadly cuneate-flabellate, thick, transversely convex, and 2-2.5 × 3-3.5 cm in size, often resinous, puberulent when young, soon glabrous, and faintly striate abaxially.
Bracts are exserted (protrude), not reflexed, and lingulate (shaped like a tongue), with the cusp longer than lateral lobes.
Seeds are brown, ovoid-conical, 1-1.2 cm × ca. 6 mm in size; the wing pale brown, obovate, and 1-1.4 cm in size.
These trees typically grow to 100 meters tall and the trunk to 4 meters diameter at breast height (d.b.h.) in native range. The Rocky Mountain subspecies is smaller, rarely over 40 meters tall and 1.5 meters diameter.
The bark is dark gray-brown or blackish green, smooth, with resin blisters, aging rough and scaly with deep longitudinal fissures.
Branchlets are initially light yellow, becoming red-brown when dry, slightly pubescent.
Leaves are dark green adaxially in the Coast subspecies, glaucous in the Rocky Mountain subspecies; they are linear, 1.5-3.0 cm × 1-2 mm in size, and have two stomatal bands, abaxial, gray-white, apex obtuse or acuminate.
Seed cones are brown, glossy, ellipsoid-ovoid, and 5-11 × 3-4 cm in size; the Rocky Mountain subspecies has smaller cones, 4-7 cm long.
Seed scales are approximately rhombic, 2-2.5 × 2-2.5 cm in size, as long as or longer than wide.
Bracts are exserted, longer than seed scales, cusp straight or reflexed, 6-10 mm in size, tapering at apex, with lateral lobes, denticulate at margin.
This tree is similar in form to the Rocky Mountain Douglas-fir, but is genetically distinct. It is a smaller tree, 25-35 meters tall, with leaves green adaxially and with two dull grayish stomatal bands abaxially.
These trees grow to 50 meters tall and the trunk to 1 meters diameter at breast height (d.b.h).
The bark is gray or dark gray, irregularly and thickly scaly.
Branchlets are initially pale yellow or yellowish gray, aging gray, usually glabrous or slightly pubescent on main branchlets and densely pubescent on lateral branchlets.
Leaves are pectinately arranged (like the teeth of a comb ), linear and typically 2-2.5 cm × about 2 mm in size, with abaxial stomatal bands, whitish or gray-green, base broadly cuneate, and apex emarginate.
Seed cones are pale purple, glaucous, maturing purplish brown, ovoid to ellipsoid- or conical-ovoid, and 3.5-8 × 2-4.5 cm in size.
Seed scales at the middle of the cones semiorbicular, flabellate, or reniform, 2.5-3 × 3.2-4.5 (-5) cm, rusty brown pubescent abaxially, base broadly cuneate or almost truncate, concave at sides.
Bracts are reflexed, cusp narrowly triangular, about 3 mm in size, and apex obtuse.
Seeds are irregularly brown spotted abaxially, triangular-ovoid, slightly depressed, densely rusty brown pubescent adaxially; and, wing obliquely ovate or semitrullate.
Pollination occurs in April, with seed maturity October-November.
Bigcone Douglas-fir (Pseudotsuga macrocarpa)
United States - California, at 200-2400 m elevation. Habitat slopes, cliffs, and canyons, in chaparral and mixed conifer forests. The northernmost stands of the species, in Kern County, are about 35 kilometers east of the closest approach of Coast Douglas-fir. USDA hardiness zone 8.
It is a common species in the Coulter pine-Hardwood phase of California mixed conifer forests, typically found on steep north-facing slopes and in ravines, i.e., sites with relatively low fire frequency. At the lowest elevations (c. 1100 m) it occurs as scattered individuals 15-30 m tall above a closed canopy of Canyon Live Oak. At higher elevations (c. 1500 m) it becomes much more abundant (80-190 trees/ha) in a mixed Douglas-fir - oak canopy. Although often codominant with Bigcone Pine and Canyon Live Oak, it is typically found on relatively more mesic sites with lower fire frequency. Not surprisingly, then, it is also found in riparian habitats as a codominant with mesic hardwood species such as Bigleaf Maple and Western balsam poplar.
Coast Douglas-fir (Pseudotsuga menziesii)
Canada - British Columbia and Alberta
United States - Washington, Oregon, California, Idaho, Montana, Wyoming, Nevada, Utah, Colorado, Arizona, New Mexico, and Texas.
The coastal subspecies menziesii occurs from central British Columbia south along the Pacific Coast for about 2,200 km to latitude 34° 44'. USDA hardiness zone 7. The interior subspecies glauca (Rocky Mountain Douglas-fir) is found along the Rocky Mountains from British Columbia to northern Mexico, where it merges in an as-yet undetermined area into the closely related species of Mexican Douglas-fir. USDA hardiness zone 4.
Mexican Douglas-fir (Pseudotsuga lindleyana)
Mexico - Sierra Madre Occidental, Sierra Madre Oriental, and rare in the Sierra Madre del Sur, south to Oaxaca, where two small populations were recently discovered on Peña Prieta in the San Felipe Mts just north of Oaxaca City, and on Cerro Quiexobra 110 km SE of Oaxaca City, this at 16°22'N, the southernmost locality for the whole genus. The type locality is near Pachuca, Hidalgo, about 80 km NE of Mexico City.
Usually on north-facing slopes or high valleys, at 2300-3300 m, in moist conifer or mixed forests with high summer rainfall and dry winters. USDA hardiness zone 8.
|Japanese Douglas-fir (Pseudotsuga japonica)||
Japan - Honshu (Kii Peninsula) and Shikoku (Kochi Prefecture) In temperate forests at 500-1100 m elevation
Chinese Douglas-fir (Pseudotsuga sinensis)
China - south Anhui, north Fujian, north Guizhou, west Hubei, northwest Hunan, northeast Jiangxi, south Shaanxi, SE Sichuan, central and northeast Yunnan, and Zhejiang all var. sinensis. Found at elevations of 600-2800(-3300) m in China, usually in evergreen broadleaf forests
Taiwan (var. wilsoniana). In Taiwan, var. wilsoniana is scarce, scattered in the island at altitudes of 800-2500 m, usually mixing with other trees . It is reported at 1400 to 2500 m in (a) broadleaf forest, (b) mixed Hemlock, Cypress, Pine and Fagaceae forest; and (c) exposed rocky slopes.
A substantial subpopulation is protected in Lin'an County, Zhejiang, China.
Pseudotsuga forrestii - Yunnan, where it is found in the mountains at 2400-3300 m elevation
Source: Pseudotsuga, The Gymnosper Database (original sources removed). and IUCN, Red List
Economic Importance for Humans
Coast Douglas-fir is a most important timber tree, valued in both the Old and New worlds. The two intergrading varieties are sympatric in southern British Columbia and northeastern Washington. it was used by Westerners for telephone poles and railway ties among many other uses. Today, Douglas-fir is also grown for Christmas trees.
- Douglas-fir needles were made into a tea and drank by Isleta Puebloans in New Mexico to cure rheumatism.
- Douglas-fir resin was used by the Shasta in northern California to poultice cuts and the Yuki along the California coast used a decoction from spring buds to treat venereal diseases.
- The Sinkyone of California made Douglas-fir bark tea which eased colds and stomach ailments.
- The Kayenta Navaho of Arizona used the tree to treat stomach disease and headaches, although what part of the plant was used is not known. Also, historically the Kayenta Navajo ground part of tree with a certain rock and mixed it with corn seeds to insure a good crop.
- The Pueblo people used the wood to construction dwellings while the twigs were worn on various parts of dancers' costumes. Prayer sticks made of Douglas-fir wood were excavated from archeological sites in New Mexico dating back to the Anasazi.
- The White Mountain Apache used the pitch of this conifer as gum and applied it to water jugs to make them watertight. Douglas-fir roots were used in California Indian basketry.
Bigcone Douglas-fir is a tree of scattered occurrence and of no concern for timber, but is valuable for esthetics and watershed protection.
Threats & Conservation Status
|Bigcone Douglas-fir (Pseudotsuga macrocarpa)||Lower Risk/near threatened|
|Coast Douglas-fir (Pseudotsuga menziesii)||Least concern|
|Japanese Douglas-fir (Pseudotsuga japonica)||Vulnerable|
|Chinese Douglas-fir (Pseudotsuga sinensis)||Vulnerable - The timber is extracted extensively throughout the species' range but most thoroughly in accessible areas. Trees are also being lost through habitat destruction for expanding agricultural activities. In Taiwan the forest is being extensively cleared for apple and peach orchards. The timber is extracted extensively throughout the species' range but most thoroughly in accessible areas.|
Source: Conifer Specialist Group 1998. Pseudotsuga sinensis. In: IUCN 2011. IUCN Red List of Threatened Species.
- Anonymous. 1986. List-Based Rec., Soil Conserv. Serv., U.S.D.A. Database of the U.S.D.A., Beltsville.
- C.Michael Hogan. 2008. Pseudotsuga menziesii, Dougas fir. GlobalTwitcher. ed. N.Stromberg.
- P.A.Munz P. A. & D. D. Keck. 1959. Cal. Fl. 1–1681. University of California Press, Berkeley. http://www.tropicos.org/Reference/1717
- P.A.Munz P. A. 1974. Fl. S. Calif. 1–1086. University of California Press, Berkeley.
- Flora of China Editorial Committee. 1999. Fl. China 4: 1–453. Science Press & Missouri Botanical Garden Press, Beijing & St. Louis. 
- Flora of North America Editorial Committee, e. 1993. Pteridophytes and Gymnosperms. 2: i–xvi, 1–475. In Fl. N. Amer. Oxford University Press, New York.
- Pseudotsuga, The Gymnosper Database (accessed December 19, 2012)
- Conifer Specialist Group 1998. Pseudotsuga sinensis. In: IUCN 2011. IUCN Red List of Threatened Species. Version 2011.2. Downloadedon 18December2011.
- Jepson Manual. 1993. Genus Pseudotsuga. University of California, Berkeley
- Wu Zheng-yi and Peter H. Raven (eds.). 1999. Flora of China, Volume 4. Beijing: Science Press; St. Louis: Missouri Botanical Garden.
- Lipscomb, Barney. 1993. Pseudotsuga. Flora of North America Editorial Committee (eds.): Flora of North America North of Mexico, Vol. 2. Oxford University Press.
- Iwatsuki K., Yamazaki T., Boufford, D.E., and Ohba H. (eds.). 1995. Flora of Japan, Volume 1. Pteridophyta and Gymnospermae. Tokyo, Japan: Kodansha. Pp. xv and 263-288.
- Burns, R.M. and B.H. Honkala. 1990. Silvics of North America, Vol. 1, Conifers. Washington DC: U.S.D.A. Forest Service Agriculture Handbook 654. ,
- Robert S. Thompson, Katherine H. Anderson and Patrick J. Bartlein. 1999. Atlas of Relations Between Climatic Parameters and Distributions of Important Trees and Shrubs in North America. U.S. Geological Survey Professional Paper 1650 A&B. URL=http://greenwood.cr.usgs.gov/pub/ppapers/p1650-a/pages/conifers.html,
- James R. Griffin (1964-09). "A New Douglas-Fir Locality in Southern California". Forest Science: 317–319. http://www.ingentaconnect.com/content/saf/fs/1964/00000010/00000003/art00015. Retrieved 2010-12-31.
- Gymnosperm Database: Pseudotsuga menziesii var. menziesii (2006)
- New C-methylflavanones from Douglas-fir. G.M. Barton, Phytochemistry, Volume 11, Issue 1, January 1972, pp. 426-429, doi:10.1016/S0031-9422(00)90036-0
- C. Michael Hogan (2008) Douglas-fir: Pseudotsuga menziesii, globalTwitcher.com, ed. Nicklas Strõmberg
- Distribution of Douglas-fir
- Asimov, Eric (2007-08-15). "An Orchard in a Bottle, at 80 Proof". New York Times. http://www.nytimes.com/2007/08/15/dining/15pour.html. Retrieved 2009-02-01.
- "Pseudotsuga menziesii var. menziesii". The Gymnosperm Database. http://www.conifers.org/pi/ps/menziesii2.htm. Retrieved 2009-03-06. "This was the preferred species for Hawaiian war canoes. The Hawaiians, of course, did not log the trees; they had to rely on driftwood."
- "The Trees That Made Britain". BBC Wales.
- British Columbia Forest History Newsletter, January 1996
- The New York Times - Topics of The Times, March 7, 1897
- Meehans' Monthly: A Magazine of Horticulture, Botany and Kindred Subjects Published by Thomas Meehan & Sons, 1897 pg. 24
- The Morning Times. (Washington, D.C.), February 28, 1897, Pg. 19.
- Ron Judd (Sep. 4, 2011). "Restless Native | Giant logged long ago but not forgotten". The Seattle Times. http://seattletimes.nwsource.com/html/restlessnative/2016112972_restless05m.html. Retrieved Sep. 7, 2011.
- Kinver, Mark. "Water's the limit for tall trees". BBC News. 2008-08-13
- Oregon State University. "Douglas-fir: A 350-foot-long Drinking Straw is As Long As It Gets". 2008-08-11